Seven cutaneous and deep somatic (intramuscular) laboratory pain-induction methods, involving chemical, electrical, mechanical and thermal noxious stimuli, are being compared and evaluated in healthy adult volunteers for their potential use as reliable and objective pain measurement instruments. Each method yields four pain response parameters, namely pain threshold, drug request point, pain tolerance and pain sensitivity range. The collected pain scores will be correlated both within and between techniques and response parameters to yield a correlation matrix. This matrix will be subjected to factor analysis in order to isolate a specific pain factor, termed pain endurance. Pain induction methods and pain response parameters with the highest loadings on this specific pain factor will then be selected in order to develop a brief but valid pain measurement battery. The practical applicability of this battery of pain tests is being investigated with different, commonly used, analgesic drugs as external criteria. Both mild and moderately potent analgetics, such as aspirin, propoxyphene, acetominophen and codeine, are being used in double-blind, complete cross-over designs. Some of these pain-induction methods are also being studied with other pain treatment modalities, such as transcutaneous electrical nerve stimulation and acupuncture. The ultimate objective is to develop valid laboratory procedures for measuring and predicting clinical pain in patients with pain problems. BIBLIOGRAPHIC REFERENCES: Wolff, B.B., Kantor, T.G. & Cohen, P.: Laboratory pain induction methods for human analgesic assays. In J.J. Bonica (ed) Proceedings of the First World Congress of the International Association for the Study of Pain. Raven, N.Y., in press. Battista, A.F. & Wolff, B.B.: Differential Changes in response to laboratory pain induction following transcutaneous electrical nerve stimulation in man. In J.J. Bonica (ed) Proceedings of the First World Congress of the International Association for the Study of Pain. Raven, N.Y., in press.